The present invention relates to an eyelet buttonhole sewing machine with a housing forming a stand and an arm, a table driven in two mutually perpendicular directions and bearing an article being sewn, a clamp, for the article being sewn, fastened on the table, and a needle bar which is mounted in the arm, which is driven so as to move up and down and has a needle at its lower end.
Such a sewing machine is known, for example, from DE 41 32 586 C2. By means of a clamp for the article being sewn, the article being sewn is fixed on the table which then guides it along under the needle according to the buttonhole bead to be produced. The clamp for the article being sewn is fastened pivotably to the table by a central arm. This arm runs parallel to the longitudinal axis of the sewing machine arm, and further is arranged behind the sewing needle. The article being sewn itself can consequently only be transported over its full length transversely to the machine arm. Therefore, if a great number of buttonholes arranged one following another are to be produced using this sewing machine, this is only possible if the buttonhole bead runs transversely to the longitudinal direction of the article being sewn.
From DE-B 14 85 196, a buttonhole sewing machine is known, which has a great number of machine arms arranged in a parallel manner and at an angle of 45.degree. to the direction of transport of the article being sewn. The machine arms are arranged displaceably along a guide in the direction of transport of the article being sewn. By corresponding displacement or arrangement of the arms along this guide, buttonholes can be produced, which run in both the transverse direction and the longitudinal direction of the edge of the article being sewn or of transport of the article being sewn. It is also possible to produce a combination of buttonholes both parallel to the edge (longitudinal direction) and perpendicular to the edge (transverse direction). On account of the great number of machine arms and their design at an angle of 45.degree., the construction of this sewing machine is quite complicated. The susceptibility to faults is moreover correspondingly greater in comparison with a machine provided with only one machine arm.
DE-C 16 60 950 discloses an automatic buttonhole sewing machine, in which the stand, to which the arm is fastened, has a recess so that buttonholes running in both the transverse direction and the longitudinal direction can be sewn using this machine. However, no driven table is provided, on which the article being sewn can be fixed. The clamp for the article being sewn is fastened to the arm, so that its fastening point is above the article being sewn and the article being sewn can pass to the recess in the stand.
DE 35 33 022 A1 discloses an eyelet buttonhole sewing machine, in which two clamps arranged symmetrically in relation to the longitudinal axis of the sewing machine arm are provided for securing the article being sewn.
DE 26 50 334 (equivalent to U.S. Pat. No. 4,131,074) and DE 14 85 118 disclose other sewing machines of interest.